As described by William Perkins in "On the Identification of a Witch," there were very few, though key, forms of evidence that could lead to a person's conviction of performing witchcraft. If applied properly to a trial, then the accused could only be convicted using what Perkins termed "true proofs." In the trial of one of the accused Salem witches, Bridget Bishop, it seems as if the actual conviction was based on what Perkins called "less sufficient proofs" and "presumptions." That means that the guidelines given by Perkins were used inaccurately during the examination of Bridget Bishop and so led to the conviction of a person who was more than likely innocent. .
The main argument of Bridget Bishop being a witch was based on spectral evidence that should only have been submitted as a less sufficient proof. Mary Walcott and her brother, Jonathan, state that the latter "struck her [i.e., Bishop's] appearance and saw that he had tore her coat in striking and heard it tear. Upon some search in the Court, a rent that seems to answer what was alleged was found" (385). At the time of the attack upon Jonathan Walcott, Bishop was said to be nothing more than an apparition. In this case, the evidence should have been submitted as purely spectral but instead seemed to be one of the examination's greater points. Also, Jonathan testifies that "the sword that he struck at Goody Bishop with was not naked but was within the scabbard" (387). One might say that it is impossible to damage a mere apparition and that it is even more impossible to do so with a sheathed sword. If this evidence had been categorized correctly, it would have fallen under a "less sufficient proof" which could contribute to a case but not warrant a conviction without a true proof.
Two more closely related considerations arose towards the end of the examination that were in fact nothing more than presumptions, but were used as main points.
